The Width of a Human Hair, Part 2

So, on the subject of my brief post the other day, what’s the best way to visualise the nanometre scale? I’m asking myself this as someone interested in science writing and reporting.

In this nice video on youtube, there are two explanations of just how small a nanometre is. The first, one billionth of a metre is the true definition, 0.000000001 metres. Obviously pretty small. The second is the fraction of the width of a human hair.

Aside from he pedantic point I made the other day that the width of a human hair can be quite varied, my real problem is that when I think of a hair, I think of something long and thin. The analogy doesn’t work for thin sheets or small balls- the mental images don’t match up.

Obviously, people need to be concise, but maybe there is a better way. One of the key principles of nano materials is that their size and shape determines their properties. This is because at the nano scale, structures can be made of dozens of atoms, rather than millions or billions. Individual atoms are much more important.

So rather than saying that something is small compared to a hair, why not emphasise that nano materials approach the dimensions of individual atoms? It makes the same point, that it’s really small, but just gives a little insight into what’s going on.

It’s incredible that we can work on this scale- atoms are the smallest objects we can manipulate mechanically- let’s not water it down with weak analogies.

In other news, the BBC reported yesterday that devices could be made using the principles of salad cream. It’s a beautiful example of a mangled analogy!

4 Comments on “The Width of a Human Hair, Part 2”

Mr. Hayton:
You are obviously well versed in the intricate details of the nanometer scale – something I never knew existed until now. I found your above blog, both informative and enjoyable. Thank you for showing us that there’s much more to human hair than just shampoo and coloring.